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The latest evidence for practice

Una Adderley
Senior Lecturer in Research Methods
Teeside University

Choice picks from the research journals, with
some choice comment...

Does taking aspirin daily reduce the risk of dying from cancer?
Although some causative factors have been identified for cancer (such as smoking) there are still many unknown. Studies in animals have suggested that aspirin may reduce the incidence of cancer but the effect in humans has been unclear.

This systematic review sought randomised, controlled trials that had considered the effect of taking for aspirin for four years. All studies had followed up the participants for at least five years. Eight trials were considered with a total of 25,570 patients and 674 cancer deaths, which had originally sought to identify the effect of low-dose aspirin in preventing vascular disease. Three of the trials had data for 20 years of follow-up. The participants were predominantly male, aged from 51-67 years. The daily aspirin dose ranged from 75-500 mg and most trials compared aspirin with a placebo. The studies were sufficiently similar for the results to be pooled for meta-analysis which showed that daily aspirin reduced cancer deaths by 20% and that longer treatment was associated with
greater benefits.

A commentary notes that this study appears to confirm that low-dose aspirin reduces the risk of death from cancer and that the risk of stomach bleeds (as a side-effect of aspirin) may be outweighed by this benefit. However, as women formed a relatively low proportion of the study population, it cannot be assumed that these benefits will extend to cancers that affect women such as breast and gynaecological cancers. 

Rothwell PM, Fowkes FG, Belch JF et al. Effect of daily aspirin on long-term
risk of death due to cancer: analysis of individual patient data from randomised trials. Lancet 2011; 377:31-41.

Coleman EA. Evid Based Nurs 2011;14(3):71.

How effective are interventions aimed at preventing teenagers
from smoking? 
Adolescents who smoke are prone to becoming nicotine dependent and are more likely to become long-term smokers. Therefore, discouraging tobacco use at an early stage is important in discouraging smoking levels at a population level.  

This randomised, controlled trial sought to discover whether an ‘implementation intentions' intervention reduced smoking in adolescents. The four-year study recruited 1,551 participants from four English schools, randomly allocated into one of four groups: the implementation intentions intervention; a self-efficacy manipulation intervention; or one of two control groups. The participants in the implementation intentions intervention focused on supporting participants in planning how, when and where they should resist smoking. The self-efficacy manipulation intervention focused on supporting participants in planning how they should communicate in difficult situations when refusing to smoke. The control groups asked students to complete work relating to planning schoolwork.

The results showed that the implementation intentions intervention reduced the chances of being a smoker at 48 months after the intervention more than the other intervention or controls. In particular, this was particularly effective in adolescents aged between 15 and 16 years old.

A commentary notes that the results of study are in line with results of other studies that show that brief and well-structured interventions are effective in changing the behaviour of adolescents. It also notes that interventions that aim at risk prevention appear to be more effective when commenced early in adolescence and when they continue over some years with frequent review and follow-up.

Conner M, Higgins AR. Long-term effects of implementation intentions on prevention of smoking uptake among adolescents: a cluster randomized, controlled trial. Health Psychol 2010;29:529-38.

Ferreira M. Evid Based Nurs 2001;14(3):81.